Guardrails are typically installed along highways as components in roadway safety barrier systems. The guardrails commonly used are usually formed as strips of material, typically twelve (12) gauge galvanized steel. Other materials commonly used in guardrail fabrication include aluminum, steel, fiberglass, or even synthetic materials. Most segments of guardrail are approximately twelve (12) feet in length and about ninety (90) pounds in weight.
At least one configuration of a guardrail used includes a corrugation forming an undulating cross section. The undulating cross section is employed in its capacity to absorb energy from the impact of an out of control vehicle. Such energy absorption is desired in an effort to prevent the vehicle from leaving the roadway or at least to influence the direction of the vehicle prior to it leaving the roadway. Typically, corrugated beams are about nine (9) inches wide, have two crowns and are shaped substantially like the letter “W”. An alternate corrugated guardrail embodiment is known in the industry as a thrie-beam guardrail. Thrie-beam guardrails typically have three crowns and are generally about one-third (⅓) wider than a conventional, two-crown, or “W”, guardrail.
In most roadway safety barrier systems, a plurality of guardrails are typically linked together at their distal ends, either end to end, or overlapping, and are supported by a plurality of vertically oriented support posts. Among the support post configurations typically used are “I-beam,” round or square posts. The support posts used may be fabricated from a variety of materials including wood, metals such as aluminum, steel, etc. Some support posts may also be formed from polymer or fiberglass materials. In place, driven into the ground a distance from the edge of the roadway and from one another, the support posts will typically yield under a certain amount of pressure either by moving within the ground or by bending in accordance with the deformation of the guardrail. Preferably, the support posts do not break off at ground level. Yielding or bending is preferred in an effort to assist the guardrail in dissipating the impact force received from an out of control vehicle.
In a typical roadway safety barrier system, a spacer block is disposed between the guardrail and the support post such that the guardrail may be maintained a distance from the support post. The spacing provided by the spacer block preferably helps keep an automobile's wheels from coming into contact with the support posts and initiating a roll of the vehicle. In addition, the guardrail provides a rail or track for guiding the vehicle and providing at least some response time for the driver to regain control of the vehicle.
Conventional spacer blocks are typically made of wood. However, wood as a material for spacer blocks has many shortcomings. Among wood's shortcomings as a spacer block material are that it deteriorates over time, it is excessively heavy, it can give installers splinters and it typically contracts and expands with seasonal changes. In addition, wood tends to leach out the chemicals typically used for pressure treatment, which chemicals may be toxic to the environment. While there are some plastic spacer block substitutes on the market, they are generally deficient in that they are typically wood block designs formed from plastic.
In most installation instances, it requires two to three people to attach a twelve (12) foot section of guard railing to support posts when using conventional spacer blocks. In the effort, installation typically requires one person to hold the guardrail while another person aligns and holds the spacer block in position. A third person is often required to insert bolts or other attachment means through each system piece for securitization thereof.